Implantable medical devices (IMDs) are devices designed to be implanted into a patient. Some examples of these devices include cardiac rhythm management devices such as implantable pacemakers and implantable cardioverter defibrillators (ICDs). The devices are used to treat patients using electrical therapy and to aid a physician in patient diagnosis through internal monitoring of a patient's condition. The devices include electrical leads in communication with sense amplifiers to monitor electrical activity within a patient and often include sensors to monitor other internal patient parameters. In general, the sensors convert sensed internal parameters into electrical signals. The electrical signals monitored within the patient and the electrical signals from the sensors can be quantified by analog-to-digital converters and stored in the IMD as data.
Implantable medical devices are able to communicate with external devices using wireless communication methods such as radio frequency (RF) or mutual inductance. The external devices are often external programmers that use wireless communication to change performance parameters in the implantable device. The implantable device also transmits the stored data to an external device using the wireless communication.
As technology used in the implantable medical devices increases, the devices collect data from multiple leads and multiple sensors. Potentially, this results in large amounts of data to be collected by the implantable device and transmitted to the external device. Additionally, the data may be collected from different types of sensors at different rates, or processing may be done on the collected data by the implantable device before the data is transmitted. This complicates the task of making efficient use of resources within the implantable device such as memory and the wireless communication interface. It also results in the data being available from the implantable device at different times and complicates the task of data management for caregivers. What is needed is an improved method of managing data available from implantable medical devices.